/src/openssl/crypto/bn/bn_conv.c

Source (jump to first uncovered line)
/*
 * Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#include <openssl/err.h>
#include "crypto/ctype.h"
#include "bn_local.h"

static const char Hex[] = "0123456789ABCDEF";

/* Must 'OPENSSL_free' the returned data */
char *BN_bn2hex(const BIGNUM *a)
{
    int i, j, v, z = 0;
    char *buf;
    char *p;

    if (BN_is_zero(a))
        return OPENSSL_strdup("0");
    buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
    if (buf == NULL)
        goto err;
    p = buf;
    if (a->neg)
        *p++ = '-';
    for (i = a->top - 1; i >= 0; i--) {
        for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
            /* strip leading zeros */
            v = (int)((a->d[i] >> j) & 0xff);
            if (z || v != 0) {
                *p++ = Hex[v >> 4];
                *p++ = Hex[v & 0x0f];
                z = 1;
            }
        }
    }
    *p = '\0';
 err:
    return buf;
}

#ifndef FIPS_MODULE
/* No BIO_snprintf in FIPS_MODULE */
/* Must 'OPENSSL_free' the returned data */
char *BN_bn2dec(const BIGNUM *a)
{
    int i = 0, num, ok = 0, n, tbytes;
    char *buf = NULL;
    char *p;
    BIGNUM *t = NULL;
    BN_ULONG *bn_data = NULL, *lp;
    int bn_data_num;

    /*-
     * get an upper bound for the length of the decimal integer
     * num <= (BN_num_bits(a) + 1) * log(2)
     *     <= 3 * BN_num_bits(a) * 0.101 + log(2) + 1     (rounding error)
     *     <= 3 * BN_num_bits(a) / 10 + 3 * BN_num_bits / 1000 + 1 + 1
     */
    i = BN_num_bits(a) * 3;
    num = (i / 10 + i / 1000 + 1) + 1;
    tbytes = num + 3;   /* negative and terminator and one spare? */
    bn_data_num = num / BN_DEC_NUM + 1;
    bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG));
    buf = OPENSSL_malloc(tbytes);
    if (buf == NULL || bn_data == NULL)
        goto err;
    if ((t = BN_dup(a)) == NULL)
        goto err;

    p = buf;
    lp = bn_data;
    if (BN_is_zero(t)) {
        *p++ = '0';
        *p++ = '\0';
    } else {
        if (BN_is_negative(t))
            *p++ = '-';

        while (!BN_is_zero(t)) {
            if (lp - bn_data >= bn_data_num)
                goto err;
            *lp = BN_div_word(t, BN_DEC_CONV);
            if (*lp == (BN_ULONG)-1)
                goto err;
            lp++;
        }
        lp--;
        /*
         * We now have a series of blocks, BN_DEC_NUM chars in length, where
         * the last one needs truncation. The blocks need to be reversed in
         * order.
         */
        n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT1, *lp);
        if (n < 0)
            goto err;
        p += n;
        while (lp != bn_data) {
            lp--;
            n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT2, *lp);
            if (n < 0)
                goto err;
            p += n;
        }
    }
    ok = 1;
 err:
    OPENSSL_free(bn_data);
    BN_free(t);
    if (ok)
        return buf;
    OPENSSL_free(buf);
    return NULL;
}
#endif

int BN_hex2bn(BIGNUM **bn, const char *a)
{
    BIGNUM *ret = NULL;
    BN_ULONG l = 0;
    int neg = 0, h, m, i, j, k, c;
    int num;

    if (a == NULL || *a == '\0')
        return 0;

    if (*a == '-') {
        neg = 1;
        a++;
    }

    for (i = 0; i <= INT_MAX / 4 && ossl_isxdigit(a[i]); i++)
        continue;

    if (i == 0 || i > INT_MAX / 4)
        return 0;

    num = i + neg;
    if (bn == NULL)
        return num;

    /* a is the start of the hex digits, and it is 'i' long */
    if (*bn == NULL) {
        if ((ret = BN_new()) == NULL)
            return 0;
    } else {
        ret = *bn;
        if (BN_get_flags(ret, BN_FLG_STATIC_DATA)) {
            ERR_raise(ERR_LIB_BN, ERR_R_PASSED_INVALID_ARGUMENT);
            return 0;
        }
        BN_zero(ret);
    }

    /* i is the number of hex digits */
    if (bn_expand(ret, i * 4) == NULL)
        goto err;

    j = i;                      /* least significant 'hex' */
    m = 0;
    h = 0;
    while (j > 0) {
        m = (BN_BYTES * 2 <= j) ? BN_BYTES * 2 : j;
        l = 0;
        for (;;) {
            c = a[j - m];
            k = OPENSSL_hexchar2int(c);
            if (k < 0)
                k = 0;          /* paranoia */
            l = (l << 4) | k;

            if (--m <= 0) {
                ret->d[h++] = l;
                break;
            }
        }
        j -= BN_BYTES * 2;
    }
    ret->top = h;
    bn_correct_top(ret);

    *bn = ret;
    bn_check_top(ret);
    /* Don't set the negative flag if it's zero. */
    if (ret->top != 0)
        ret->neg = neg;
    return num;
 err:
    if (*bn == NULL)
        BN_free(ret);
    return 0;
}

int BN_dec2bn(BIGNUM **bn, const char *a)
{
    BIGNUM *ret = NULL;
    BN_ULONG l = 0;
    int neg = 0, i, j;
    int num;

    if (a == NULL || *a == '\0')
        return 0;
    if (*a == '-') {
        neg = 1;
        a++;
    }

    for (i = 0; i <= INT_MAX / 4 && ossl_isdigit(a[i]); i++)
        continue;

    if (i == 0 || i > INT_MAX / 4)
        goto err;

    num = i + neg;
    if (bn == NULL)
        return num;

    /*
     * a is the start of the digits, and it is 'i' long. We chop it into
     * BN_DEC_NUM digits at a time
     */
    if (*bn == NULL) {
        if ((ret = BN_new()) == NULL)
            return 0;
    } else {
        ret = *bn;
        BN_zero(ret);
    }

    /* i is the number of digits, a bit of an over expand */
    if (bn_expand(ret, i * 4) == NULL)
        goto err;

    j = BN_DEC_NUM - i % BN_DEC_NUM;
    if (j == BN_DEC_NUM)
        j = 0;
    l = 0;
    while (--i >= 0) {
        l *= 10;
        l += *a - '0';
        a++;
        if (++j == BN_DEC_NUM) {
            if (!BN_mul_word(ret, BN_DEC_CONV)
                || !BN_add_word(ret, l))
                goto err;
            l = 0;
            j = 0;
        }
    }

    bn_correct_top(ret);
    *bn = ret;
    bn_check_top(ret);
    /* Don't set the negative flag if it's zero. */
    if (ret->top != 0)
        ret->neg = neg;
    return num;
 err:
    if (*bn == NULL)
        BN_free(ret);
    return 0;
}

int BN_asc2bn(BIGNUM **bn, const char *a)
{
    const char *p = a;

    if (*p == '-')
        p++;

    if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
        if (!BN_hex2bn(bn, p + 2))
            return 0;
    } else {
        if (!BN_dec2bn(bn, p))
            return 0;
    }
    /* Don't set the negative flag if it's zero. */
    if (*a == '-' && (*bn)->top != 0)
        (*bn)->neg = 1;
    return 1;
}

Coverage Report

Created: 2024-02-25 06:25

Line	Count	Source (jump to first uncovered line)
1		/*
2		* Copyright 1995-2020 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (the "License"). You may not use
5		* this file except in compliance with the License. You can obtain a copy
6		* in the file LICENSE in the source distribution or at
7		* https://www.openssl.org/source/license.html
8		*/
9
10		#include <openssl/err.h>
11		#include "crypto/ctype.h"
12		#include "bn_local.h"
13
14		static const char Hex[] = "0123456789ABCDEF";
15
16		/* Must 'OPENSSL_free' the returned data */
17		char BN_bn2hex(const BIGNUM a)
18	0	{
19	0	int i, j, v, z = 0;
20	0	char *buf;
21	0	char *p;
22
23	0	if (BN_is_zero(a))
24	0	return OPENSSL_strdup("0");
25	0	buf = OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
26	0	if (buf == NULL)
27	0	goto err;
28	0	p = buf;
29	0	if (a->neg)
30	0	*p++ = '-';
31	0	for (i = a->top - 1; i >= 0; i--) {
32	0	for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
33		/* strip leading zeros */
34	0	v = (int)((a->d[i] >> j) & 0xff);
35	0	if (z \|\| v != 0) {
36	0	*p++ = Hex[v >> 4];
37	0	*p++ = Hex[v & 0x0f];
38	0	z = 1;
39	0	}
40	0	}
41	0	}
42	0	*p = '\0';
43	0	err:
44	0	return buf;
45	0	}
46
47		#ifndef FIPS_MODULE
48		/* No BIO_snprintf in FIPS_MODULE */
49		/* Must 'OPENSSL_free' the returned data */
50		char BN_bn2dec(const BIGNUM a)
51	0	{
52	0	int i = 0, num, ok = 0, n, tbytes;
53	0	char *buf = NULL;
54	0	char *p;
55	0	BIGNUM *t = NULL;
56	0	BN_ULONG bn_data = NULL, lp;
57	0	int bn_data_num;
58
59		/*-
60		* get an upper bound for the length of the decimal integer
61		* num <= (BN_num_bits(a) + 1) * log(2)
62		* <= 3 * BN_num_bits(a) * 0.101 + log(2) + 1 (rounding error)
63		* <= 3 * BN_num_bits(a) / 10 + 3 * BN_num_bits / 1000 + 1 + 1
64		*/
65	0	i = BN_num_bits(a) * 3;
66	0	num = (i / 10 + i / 1000 + 1) + 1;
67	0	tbytes = num + 3; /* negative and terminator and one spare? */
68	0	bn_data_num = num / BN_DEC_NUM + 1;
69	0	bn_data = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG));
70	0	buf = OPENSSL_malloc(tbytes);
71	0	if (buf == NULL \|\| bn_data == NULL)
72	0	goto err;
73	0	if ((t = BN_dup(a)) == NULL)
74	0	goto err;
75
76	0	p = buf;
77	0	lp = bn_data;
78	0	if (BN_is_zero(t)) {
79	0	*p++ = '0';
80	0	*p++ = '\0';
81	0	} else {
82	0	if (BN_is_negative(t))
83	0	*p++ = '-';
84
85	0	while (!BN_is_zero(t)) {
86	0	if (lp - bn_data >= bn_data_num)
87	0	goto err;
88	0	*lp = BN_div_word(t, BN_DEC_CONV);
89	0	if (*lp == (BN_ULONG)-1)
90	0	goto err;
91	0	lp++;
92	0	}
93	0	lp--;
94		/*
95		* We now have a series of blocks, BN_DEC_NUM chars in length, where
96		* the last one needs truncation. The blocks need to be reversed in
97		* order.
98		*/
99	0	n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT1, *lp);
100	0	if (n < 0)
101	0	goto err;
102	0	p += n;
103	0	while (lp != bn_data) {
104	0	lp--;
105	0	n = BIO_snprintf(p, tbytes - (size_t)(p - buf), BN_DEC_FMT2, *lp);
106	0	if (n < 0)
107	0	goto err;
108	0	p += n;
109	0	}
110	0	}
111	0	ok = 1;
112	0	err:
113	0	OPENSSL_free(bn_data);
114	0	BN_free(t);
115	0	if (ok)
116	0	return buf;
117	0	OPENSSL_free(buf);
118	0	return NULL;
119	0	}
120		#endif
121
122		int BN_hex2bn(BIGNUM *bn, const char a)
123	32	{
124	32	BIGNUM *ret = NULL;
125	32	BN_ULONG l = 0;
126	32	int neg = 0, h, m, i, j, k, c;
127	32	int num;
128
129	32	if (a == NULL \|\| *a == '\0')
130	0	return 0;
131
132	32	if (*a == '-') {
133	0	neg = 1;
134	0	a++;
135	0	}
136
137	8.22k	for (i = 0; i <= INT_MAX / 4 && ossl_isxdigit(a[i]); i++)
138	8.19k	continue;
139
140	32	if (i == 0 \|\| i > INT_MAX / 4)
141	0	return 0;
142
143	32	num = i + neg;
144	32	if (bn == NULL)
145	0	return num;
146
147		/* a is the start of the hex digits, and it is 'i' long */
148	32	if (*bn == NULL) {
149	0	if ((ret = BN_new()) == NULL)
150	0	return 0;
151	32	} else {
152	32	ret = *bn;
153	32	if (BN_get_flags(ret, BN_FLG_STATIC_DATA)) {
154	0	ERR_raise(ERR_LIB_BN, ERR_R_PASSED_INVALID_ARGUMENT);
155	0	return 0;
156	0	}
157	32	BN_zero(ret);
158	32	}
159
160		/* i is the number of hex digits */
161	32	if (bn_expand(ret, i * 4) == NULL)
162	0	goto err;
163
164	32	j = i; /* least significant 'hex' */
165	32	m = 0;
166	32	h = 0;
167	544	while (j > 0) {
168	512	m = (BN_BYTES * 2 <= j) ? BN_BYTES * 2 : j;
169	512	l = 0;
170	8.19k	for (;;) {
171	8.19k	c = a[j - m];
172	8.19k	k = OPENSSL_hexchar2int(c);
173	8.19k	if (k < 0)
174	0	k = 0; /* paranoia */
175	8.19k	l = (l << 4) \| k;
176
177	8.19k	if (--m <= 0) {
178	512	ret->d[h++] = l;
179	512	break;
180	512	}
181	8.19k	}
182	512	j -= BN_BYTES * 2;
183	512	}
184	32	ret->top = h;
185	32	bn_correct_top(ret);
186
187	32	*bn = ret;
188	32	bn_check_top(ret);
189		/* Don't set the negative flag if it's zero. */
190	32	if (ret->top != 0)
191	32	ret->neg = neg;
192	32	return num;
193	0	err:
194	0	if (*bn == NULL)
195	0	BN_free(ret);
196	0	return 0;
197	32	}
198
199		int BN_dec2bn(BIGNUM *bn, const char a)
200	0	{
201	0	BIGNUM *ret = NULL;
202	0	BN_ULONG l = 0;
203	0	int neg = 0, i, j;
204	0	int num;
205
206	0	if (a == NULL \|\| *a == '\0')
207	0	return 0;
208	0	if (*a == '-') {
209	0	neg = 1;
210	0	a++;
211	0	}
212
213	0	for (i = 0; i <= INT_MAX / 4 && ossl_isdigit(a[i]); i++)
214	0	continue;
215
216	0	if (i == 0 \|\| i > INT_MAX / 4)
217	0	goto err;
218
219	0	num = i + neg;
220	0	if (bn == NULL)
221	0	return num;
222
223		/*
224		* a is the start of the digits, and it is 'i' long. We chop it into
225		* BN_DEC_NUM digits at a time
226		*/
227	0	if (*bn == NULL) {
228	0	if ((ret = BN_new()) == NULL)
229	0	return 0;
230	0	} else {
231	0	ret = *bn;
232	0	BN_zero(ret);
233	0	}
234
235		/* i is the number of digits, a bit of an over expand */
236	0	if (bn_expand(ret, i * 4) == NULL)
237	0	goto err;
238
239	0	j = BN_DEC_NUM - i % BN_DEC_NUM;
240	0	if (j == BN_DEC_NUM)
241	0	j = 0;
242	0	l = 0;
243	0	while (--i >= 0) {
244	0	l *= 10;
245	0	l += *a - '0';
246	0	a++;
247	0	if (++j == BN_DEC_NUM) {
248	0	if (!BN_mul_word(ret, BN_DEC_CONV)
249	0	\|\| !BN_add_word(ret, l))
250	0	goto err;
251	0	l = 0;
252	0	j = 0;
253	0	}
254	0	}
255
256	0	bn_correct_top(ret);
257	0	*bn = ret;
258	0	bn_check_top(ret);
259		/* Don't set the negative flag if it's zero. */
260	0	if (ret->top != 0)
261	0	ret->neg = neg;
262	0	return num;
263	0	err:
264	0	if (*bn == NULL)
265	0	BN_free(ret);
266	0	return 0;
267	0	}
268
269		int BN_asc2bn(BIGNUM *bn, const char a)
270	0	{
271	0	const char *p = a;
272
273	0	if (*p == '-')
274	0	p++;
275
276	0	if (p[0] == '0' && (p[1] == 'X' \|\| p[1] == 'x')) {
277	0	if (!BN_hex2bn(bn, p + 2))
278	0	return 0;
279	0	} else {
280	0	if (!BN_dec2bn(bn, p))
281	0	return 0;
282	0	}
283		/* Don't set the negative flag if it's zero. */
284	0	if (a == '-' && (bn)->top != 0)
285	0	(*bn)->neg = 1;
286	0	return 1;
287	0	}